Sponge Cake No. 2

• 3 eggs
• 1 scant cup sugar
• 1 tablespoonful hot water

Beat the yolks until thick and light; add sugar gradually and continue beating; then add water and vinegar; add the salt to the whites and beat until very stiff; sift the flour with baking powder three times; add the flavoring and fold in the flour and the beaten whites alternately as gently as possible. Bake about 30 minutes in slow oven until well risen; then increase the heat. Invert to cool